412 THE VOYAGE OF H.M.S. CHALLENGER. 



The genus TriscMzostoma is thus defined : — " Caput antics in rostrum frontale crassum, latum, 

 in apice rotundatum, productum. Antenure inferiores artioulo 4to longitudinem 5ti super- 

 anti. Pedes Imi paris manu permagna, inflata, ovata ; ungve non in angulo inferiore 

 anteriore, ut solito, sed in angulo inferiore posteriore inarticulato, antice verso. Pedes 4ti 

 paris articulo 3tio valde dilatato et latiore quam pedum 3tu paris. Epimerum Imum 

 parvum. Epimerum 2dum deorsum valde dUatatum, Imum partim tegens. Oculi 

 permagni. Appendix caudalis lata." In regard to this genus see Note on Costa, 1853. 



1872. Brandt, Alexander. 



Bericht iiber die Cyamiden des zoologischen Museums der Kaiserlichen 



Akademie der Wissenschaften zu St Petersburg. " ., ^.^ 1872. Melanges Bio- 



° 4 Jum ° 



logiques tires du Bulletin de I'Academie imperiale des sciences de St.-Petersbourg. 



Tome VIII. pp. 673-702. (Aus dem Bulletin, T. XVIII, pp. 113-133. Oct. 



1872.) 



A new species, " Cyamus Kessleri," is figured and described, with the following diagnosis, 

 " Corpus maris pyriforme, feminse oh verso- pyriforme vel rhomboideum. Maris primi 

 paris manus dente armatae, feminae fere edentulae. In utroque sexu manus secundi paris 

 duobus dentibus munitse, quorum basalis multo major. Branchia simplicia, elongata, 

 longitudine coi-pus fere aequantia. In mare appendicum branchialium sex paria insequalia. 

 Habitat in sinu Metschigmensi Maris Beringii, in Balsnis." Liitken considers that the 

 accessory branohise on tlie third and fourth segments are double, not triple, and that Brandt 

 has confused ■with these appendages the postero-lateral angles of the segment which form a 

 process bent downwards and forwards. 



Cyamus ovalis, Roussel de Vauzeme, is recognised as including " Cijamus Ehijtinx (?)" which 

 in 1871 Brandt supposed that he had re-discovered, though with notice of its great 

 resemblance to Cyamus ovalis. 



The name Cyamus ceti, auctorum, is upheld for Onisciis ceti, Lin., against the proposal of 

 Liitken to institute the designation Cyamiis mysticeti. For Cyamus ceti, Sp. Bate (Catal. 

 Amph. Crust, [p. 366, pi. Iviii. fig. 2), a very narrow elongate form from Talcahuna, which 

 has nothing in common with Oidscus ceti, Lin., he gives a name proposed by Liitken, 

 Cyamus pacificus. Without absolutely deciding, Brandt seems inclined to regard Cyamus 

 mmiodontis, Liitken, as a variety of Cyamus ceti (to which Liitken himself regards it as 

 "valde affinis"), and to agree with Bate and Westwood (Brit. Sess. Crust, vol. ii. p. 86) in 

 making Cyamus erratieus, Roussol de Vauzt>me, a synonym of the same Cyamus ceti, which 

 Liitken regards as a very decided error. Brandt notes that Cyamus hoojns, Liitken, is 

 recognised by its author as in close relationship to Cyamus erratieus, and this latter he is 

 ■willing to regard as a link between Cyamus ceti and Cyamits boopts, leaving it perhaps an 

 open question whether they may not all be one species. Cyamus glohicijntis, Liitken, he 

 thinks probably identical with " Cyamus Delphini," Guerin (Icon, du Eegne Anim. T. III. 

 p. 25, pL xx'riii. fig. 5). Eemarks are made on Cyamus nodosus, Liitken, and Cyamus 

 gracilis, Eouss. de Vauzeme. Cyamus thom2')soni, Gosse, which Liitken transferred to a new 

 genus, under the name of Platycyamus ihompscmi, Brandt would have been content to leave 

 united to the other Cyami. 



